John M. Tobin's research while affiliated with Dublin City University and other places

Publications (51)

Article
Full-text available
Nanostructured titania supported on activated carbon (AC), termed as integrated photocatalytic adsorbents (IPCAs), were prepared by ultrasonication and investigated for the photocatalytic degradation of acetaminophen (AMP), a common analgesic and antipyretic drug. The IPCAs showed high affinity towards AMP (in dark adsorption studies), with the amo...
Article
Two separate methods were used to prepare a tetra(4-carboxyphenyl)porphyrin (TCPP)-TiO2 composite. In method A TCPP was absorbed onto TiO2 in methanol at room temperature, whilst in method B TCPP was absorbed onto TiO2 in dimethylformamide (DMF) at reflux. Both composites exhibited the same physical and chemical characteristics as shown by FT-IR, S...
Article
Nitrate is naturally found within the environment as part of the nitrogen cycle. However, anthropogenic inputs have greatly increased nitrate loads within ground and surface waters. This has had a severe impact on aquatic ecosystems and has given rise to health considerations in humans and livestock. Therefore, the identification of nitrate sources...
Chapter
Scientific studies using titanium dioxide photocatalysis to purify water began almost four decades ago and since then research effort has diversified into several different approaches. One of the newest methods is combining titanium dioxide and an adsorbent material to create integrated photocatalytic adsorbents (IPCAs). This chapter surveys and c...
Article
A SPE-LC-MS/MS method was developed and validated for the determination of three active pharmaceutical ingredients [API A (3-([2-(diaminomethyleneamino)thiazol-4-yl]methylthio)-N′-sulfamoyl propanimid amide, API B 5-[(2 R)-2-[2-(2-ethoxyphenoxy)ethylamino]propyl]-2-methoxybenzenesulfonamide hydrochloride, API C 1-azabicyclo[2.2.2]octan-8-yl (1S)-1-...
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In recent years, concerns about the occurrence and fate of active pharmaceutical ingredients, solvents, intermediates and raw materials that could be present in water and wastewater including pharmaceutical industry wastewater has gained increasing attention. Traditional wastewater treatment methods, such as activated sludge, are not sufficient for...
Article
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The aim of this work is to establish baseline levels of pharmaceuticals in three wastewater treatment plant (WWTP) streams in the greater Dublin region to assess the removal efficiency of the selected WWTPs and to investigate the existence of any seasonal variability. Twenty compounds including several classes of antibiotics, acidic and basic pharm...
Article
Full-text available
Activated carbon-supported TiO(2) nanoparticles, termed integrated photocatalytic adsorbents (IPCAs), were prepared using an ultrasonic impregnation technique and investigated for the photocatalytic degradation of amoxicillin (AMO), a β-lactam antibiotic. The IPCAs had high adsorption affinity for AMO with the amount adsorbed proportional to the Ti...
Article
Full-text available
Integrated photocatalytic adsorbents (IPCAs) comprised of nanocrystalline titanium dioxide (TiO2) and activated carbon (AC) were prepared using an ultrasonic impregnation technique. The IPCAs were characterised by scanning electron microscopy (SEM) and Fourier-transform infrared (FT-IR) spectroscopy and were employed as catalysts for the photodegra...
Article
Integrated photocatalytic adsorbents (IPCAs) based on TiO2-activated carbon synthesized by an ultrasonic impregnation technique have been used for the photodegradation of indomethacin (IND) in aqueous solutions. The IPCAs in dark adsorption studies had high affinity toward IND with the amount adsorbed proportional to the TiO2 loading. The adsorptio...
Book
Full-text available
A total of 61 PPCPs were chosen to encompass a wide variety of therapeutic classes specifically deriving from antibiotics, analgesics, non-steroidal anti inflammatory drugs (NSAIDS), beta-blockers, anti-psychotics and illicit drugs of abuse. Many of these compounds were chosen based on sales data for the Republic of Ireland (Irish Medicines Board)...
Article
An investigation of sedimentary matrices in a polluted Irish river and estuary was undertaken to determine the distribution both spatially, and more importantly seasonally, of metal and organometal contamination on a monthly basis over 2 years. No previous investigations in Ireland have undertaken such a detailed analytical regime. The Tolka River...
Article
Aquatic pollution by metals is of concern because of various toxic effects to marine life. The Tolka Estuary, Co. Dublin, Ireland, is a typical Irish urban estuary. It has a significant metal loading originating from the urban environment. Results of a 25 month analysis of cadmium, copper, lead and zinc spatial and temporal distribution over 10 sam...
Article
Pharmaceuticals are continually introduced into the environment as a result of industrial and domestic use. In recent years they have emerged as environmental pollutants. An analytical method has been developed allowing for simultaneous detection and identification of 20 pharmaceutical compounds from various therapeutic classes using solid phase ex...
Article
Full-text available
An analytical method to determine a selection of 27 frequently prescribed and consumed pharmaceuticals in biosolid enriched soils and digested sludges is presented. Using a combination of pressurized liquid extraction, solid phase extraction and liquid chromatography with tandem mass spectrometry, it was possible to detect all analytes in each samp...
Article
Aquatic pollution by tributyltin (TBT) is of concern because of its high toxicity to marine life. TBT loadings of estuarine sediments may remain elevated because of long flushing times in estuaries due to their enclosed physicality. The Tolka Estuary, Co. Dublin, Ireland, is a typical Irish urban estuary. It has a significant pollution loading. The...
Article
In the process of preparation of a non-toxic metal biosorbent by entrapment of yeast cells in silica matrix by sol–gel technique, the homogeneity of yeast cell dispersion and prevention of precipitation during tetraethoxysilane pre-polymerization were found to be the parameters substantially influencing the sorption capacity for Cd2+. Ultrasonic tr...
Article
Assessment of organometal pollution requires an understanding of the various processes that influence the bioavailability and toxicity of the contaminant. Organotins may exist as both cationic species and neutral hydroxides in aqueous solution, with the formation of chloride species in the presence of Cl-. Although these species have different chem...
Article
Adsorption of metals onto biological materials, including peat, or biosorption is well-recognised as a potential alternative to conventional wastewater treatments processes. In this work, biosorption of Cr3+, Cu2+ and Cd2+ onto peat in batch systems was investigated in the pH range 2–7. The order of maximum uptake was Cr>Cu>Cd. Both H+ ion competit...
Article
As a consequence of the widespread industrial and agricultural applications of organotins, contamination of various ecosystems has occurred in recent decades. Understanding how these compounds interact with microorganisms is important in assessing the risks of organotin pollution. The organotins, tributyltin (TBT), trimethyltin (TMT) and inorganic...
Article
Reactive Black 5 was efficiently sorbed onto chitosan in acidic solutions through electrostatic attraction of anionic dye molecules to protonated amine groups of the polymer. Sorption capacities as high as 750−1000 mg of dye g-1 were obtained. The addition of chitosan to dye solution strongly affected the pH of the solution and the sorption efficie...
Article
Acid Green 25, which is a diazoic dye bearing two sulfonic groups, is efficiently sorbed on chitosan. The protonation of chitosan may explain the electrostatic attraction of this anionic dye and that its optimum pH is close to 3. Preliminary protonation of amine groups (obtained by contact with a sulfuric acid solution) reduced the variation of sol...
Article
Biosorption of Cr(3+), Cu(2+) and Cd(2+) from binary metal solutions onto peat in the batch systems was investigated at pH 4. The order of maximum uptake was Cr>or=Cu>Cd and maximum uptake levels of ca. 0.4 mmol/g were observed for chromium and copper while cadmium was taken up to a maximum of ca. 0.2 mmol/g. Co-ion competition resulted in up to 70...
Article
Activated carbon and chitosan were investigated for the sorption of several dyes. While the sorption on activated carbon was largely independent of the pH, the sorption of dyes on chitosan was controlled by the acidity of the solution. Anionic dye sorption onto chitosan occurred through electrostatic attraction on protonated amine groups. Sorption...
Article
The biosorption of three commonly used reactive dyes, from aqueous solutions by oven-dried Rhizopus arrhizus biomass was studied in a batch system with respect to pH, initial dye concentration and initial metal ion concentration. The biomass exhibited maximum dye uptake at pH 2 due to its positively charged nature at acidic pH and the anionic natur...
Article
Palladium is efficiently extracted from dilute acidic solutions using chitosan derivatives. Sorption performances are enhanced by modification of chitosan through the grafting of sulfur compounds (thiourea, rubeanic acid), which creates new chelating groups, on chitosan backbone using glutaraldehyde as a linker. A comparison of sorption isotherms a...
Article
Glutaraldehyde-cross-linked chitosan (GCC), thiourea derivative of chitosan (TGC) and rubeanic acid derivative of chitosan (RADC) have previously been shown to be very efficient at removing platinum and palladium from single component dilute acidic solutions. This study examines the competitive sorption of these metal anions in bi-component mixture...
Article
Chitosan proved efficient at removing platinum in dilute effluents. The maximum uptake capacity exceeds 280 mg g-1 (almost 1.5 mmol g-1) under optimum conditions: obtained at pH 2. A glutaraldehyde crosslinking pre-treatment is necessary to stabilize the biopolymer in acidic solutions. Sorption isotherms were studied in function of the pH, the part...
Article
Chitosan has proved efficient at removing platinum in dilute effluents. The maximum uptake capacity reaches 300 mg g-1 (almost 1.5 mmol g-1). The optimum pH for sorption is pH 2. A glutaraldehyde cross-linking pretreatment is necessary to stabilize the biopolymer in acidic solutions. Sorption isotherms have been studied as a function of pH, sorbent...
Article
A novel technique for differential extraction of subcellular ion pools from Saccharomyces cerevisiae was developed. Glyceraldehyde-3-phosphate dehydrogenase and carboxypeptidase Y were chosen as biochemical markers for the cytoplasmic and vacuolar fractions, respectively. Approximately 70% of cytosolic and vacuolar markers were detected in the rele...
Article
The presence of glucose resulted in a two- to three-fold increase in levels of Cd2+accumulated by Saccharomyces cerevisiae after 5 h compared with those observed in the absence of glucose. However, time-dependent Cd2+ uptake continued in the absence of glucose over 5 h, resulting in an appreciable increase in cellular Cd2+levels. Substantial K+ eff...
Article
Organotin compounds are ubiquitous in the environment. The general order of toxicity to microorganisms increases with the number and chain length of organic groups bonded to the tin atom. Tetraorganotins and inorganic tin have little toxicity. Because of their lipophilicity, organotins are regarded as membrane active. There is evidence that the sit...
Article
Milled-sieved and epichlorhydrin-immobilised Azolla biosorbed ca. 363 and 320mol Cu2+ g–1 from a 100 mg l–1 solution. Efficiency of Cu2+ removal by columns was in the order epichlorohydrin-immobilised Azolla>milled-sieved Azolla>untreated Azolla. The 2.5g epichlorohydrin-immobilised Azolla column demonstrated complete metal sequestration from ca.12...
Article
The biosorption of chromium by milled peat from aqueous solution was investigated between pH 2 and 7. Peat was chosen as an inexpensive and readily available biomass. Adsorption of both the cationic Cr(III) and the anionic Cr(VI) was studied. Maximum uptake of Cr(III) occurred at pH 4. At this pH, approximately 50% of the Cr(III) present was in the...
Article
Two inorganic tin compounds, as well as mono- and tri-substituted methyl-, butyl-, and phenyltins were examined for their interactions with a hydrocarbon-using strain of Candida maltosa. Neither of the inorganic tins (SnII and SnIV) inhibited growth at concentrations up to 0.8 mM while binding to the yeast cells occurred to levels of 0.3 and 0.23 m...
Article
Biomass from two fungi of the Mucorales order, laboratory cultured and immobilised Rhizopus arrhizus, and industrial waste Mucor miehei, was tested for capacity to adsorb copper from solution in batch and continuous-flow column systems. Maximum uptake levels were c 400 and 300 mmol g−1 (dry weight) respectively. Immobilisation of Rhizopus arrhizus...
Article
Inhibition of the growth of Saccharomyces cerevisiae was evident at concentrations of 0.5 mM Mn2+ or higher, but a tolerance to lower Mn2+ concentrations was observed. The inhibitory effects of 2.0 mM Mn2+ were eliminated by supplementing the medium with excess Mg2+ (10 mM), whereas addition of excess Ca2+ and K+ had negligible effect on Mn2+ toxic...
Article
Chitosan is a well-known biopolymer, whose high nitrogen content confers remarkable ability for the sorption of metal ions from dilute effluents. However, its sorption performance in both equilibrium and kinetic terms is controlled by diffusion processes. Gel bead formation allows an expansion of the polymer network, which improves access to the in...
Article
Two types of magnetic biosorbent were prepared by novel protocols from epichlorhydrin-cross-linked Saccharomyces cerevisiae cell walls and their biosorption characteristics were compared to those of non-magnetic cell walls. The magnetic biosorbents I and II were capable of binding Cu maximally to 225 and 50 mmol/g, Cd to 90 and 25 mmol/g and Ag + t...
Article
The magnesium content of Saccharomyces cerevisiae was found to vary by up to fivefold at differing stages of batch growth and during growth in the presence of differing magnesium concentrations. Excess Mg was primarily sequestered in vacuoles. Mn(2+)-uptake experiments revealed that Mg-enriched cells had a markedly reduced capacity for Mn2+ accumul...
Article
Fungal melanins are dark brown or black pigments located in cell walls. They also exist as extracellular polymers. Melanized fungi possess increased virulence and resistance to microbial attack as well as enhanced survival while under environmental stress. Melanins contain various functional groups which provide an array of multiple nonequivalent b...
Article
The transformation and accumulation of the oxyanion selenite in solution by a Penicillium species was monitored over a 2 wk period. The fungus was cultured under aerobic and acidic conditions in 5 l bioreactors at 25 °C with initial sodium selenite concentrations of 1000 μmol l−1. At this concentration selenite appeared to exert little or no toxic...
Chapter
Despite an upsurge in national and international debate on environmental issues since the Earth Summit in Rio de Janeiro in 1992, fungi, vital to the functioning of terrestrial and aquatic ecosystems, are rarely mentioned. This volume helps redress this imbalance by considering fungi in the context of the impact of humankind's activity on their hab...
Article
The greater the covalent index value of a metal ion, the greater its potential to form covalent bonds with biological ligands. In this study, freeze-dried Rhizopus arrhizus biomass was tested for its potential to adsorb the hard metal ion Sr2+ and the borderline metal ions Mn2+, Zn2+, Cd2+, Cu2+, and Pb2+ from aqueous solutions. Equilibrium metal u...
Article
This review addresses metal uptake specifically by yeast. Metal uptake may be passive, active or both, depending on the viability of the biomass, and is influenced by a number of environmental and experimental factors. Uptake is typically accompanied by a degree of ion exchange and, under certain conditions, may be enhanced by the addition of an en...
Article
Three strains ofSaccharomyces cerevisiae and one strain of aCandida sp. obtained from different industrial sources were screened for uptake of silver and copper. Considerable differences in metal uptake capacities were found between the different strains ofS. cerevisiae and betweenS. cerevisiae and theCandida sp. used. Copper uptake capacities rang...
Article
Freeze-dired, oven-dried, and nonmetabolizing live Rhizopus arrhizus biomass were tested for their capacity to adsorb the test ions, Sr2+, cd2+, and Cu2+, over the pH range 4–6. Metal uptake values for each biomass type were found to increase in the order Cu2+ > Cd2+ > Sr2+. Freeze-dried biomass proved to be the most efficient biomass type for meta...
Article
Full-text available
The applicability of the hard-and-soft principle of acids and bases in predicting metal adsorption characteristics in a biological context was investigated for metabolism-independent uptake of the metal ions Sr2+, Mn2+, Zn2+, Cu2+, Cd2+, and Tl+ by Saccharomyces cerevisiae. Metal adsorption increased with external metal concentration (5 to 50 micro...
Article
Full-text available
Laboratory and brewing strains of Saccharomyces cerevisiae were compared for metabolism-independent and -dependent Sr2+ uptake. Cell surface adsorption of Sr2+ to live cells was greater in the brewing than in the laboratory strain examined. However, uptake levels were greater in denatured (dried and ground) S. cerevisiae, and the relative affinitie...
Article
Full-text available
Estuaries are large sediment traps at the freshwater-saltwater interface. Moreover, metal loading of estuarine sediments may be elevated because of long flushing times in estuaries due to their enclosed physicality. The Tolka River Estuary, Co. Dublin, Ireland, is an urban estuary that is canalised for most of its route but has a large flat mouth w...

Citations

... Given the ability of melanin to bind to metals and degrade exotic carbohydrates, black rock fungi could be good candidates for environmental bioremediation in contaminated sites with heavy metals and radionuclides, for example, to absorb or remove harmful volatile chemicals in decorated rooms (Prenafeta-Boldú et al. 2019) or to clean up industrial effluent with radioactive contamination (Singleton and Tobin 1996). ...
... Cosmetic ingredients pose one significant ecological problem compared to other widely spread categories, such as health & pharmaceutical products; the reason behind this is their wide and uncontrolled usage by people worldwide (Gkika et al., 2022). Heavy usage connects with heavy discharge by washing and bathing; water will be the primary medium for its transformation through WWTP, soil, water streams, and different water levels (Deegan et al., 2011;Díaz-Cruz et al., 2009). Cosmetic elements such as butylated hydroxy anisole (BHA) are regularly used as preservatives in several food items and as antioxidants in medicinal products. ...
... It is well known that the pharmaceutical compounds are non-biodegradable, affecting ecological imbalance and biological functions. Furthermore, a high content of pharmaceutical chemicals in surface water [1], drinking water [2][3][4], sewage influent [5], hospital waste [6] and industrial effluents [1,4,7,8] has been reported, and generate new resistant bacteria implicating the microbial activity [9]. For example, the removal of carbamazepine by microbial treatment is difficult because of its bacterial resistance [10], causing an environmental issue [4,[11][12][13][14] and it is same for paracetamol, carbamazepine, diclofenac, and ibuprofen as classified as hazardous chemicals [15]. ...
... APAP is also an emerging environmental endocrine disruptor that is likely to pose a threat to the environment and human health [3,4]. APAP is difficult to remove using traditional bio-treatment processes due to its stable chemical structure [5,6]. ...
... Total accumulation of chromium in yeast cells was determined by ETAAS after carrying out a series of 12-h cultivations in the medium containing different chromium compounds in amounts which did not inhibit yeast growth (1 mM Cr(III) and 20 µM Cr(VI)), which was followed by the washing step with phosphate buffer in order to remove loosely bound chromium from yeast cell surface (Blackwell et al. 1999;Demirci & Pometto 2000) and by HNO 3 treatment. ...
... Almost all of these works present a batch approach for the experiments, however, most of them did not present the performance of the materials to be reused in cycles after regeneration steps. Bhattacharyya et al. [9], Haque et al. [31], and Starosud et al. [67] developed TiO 2 -zeolite materials for integrated photocatalytic adsorption operations, while Basha et al. [7], Chollom et al. [18], and Keane et al. [34] immobilized TiO 2 on activated carbon materials for the same purpose. Some works report the use of metal oxides such as SnO 2 [49], Bi 2 O 4 [42], NiFe 2 O 4 [24], and Nb 2 O 5 [68]. ...
... In highly acidic solutions, it is known that HCrO 4 − and Cr 2 O 7 2− ions prevail among Cr(VI) species [68]. Hydronium ions that surround the surface of the adsorbent at extremely low pH levels assist Cr(VI) in attaching to the adsorbent's binding sites due to their increased force of attraction. ...
... One of the major components of shrimp shell is chitin, which constitutes 16%-20% of raw shrimp shell [48]. Chitin, the second most abundant polysaccharide in nature after cellulose, has a high sorption capacity that is associated with the presence of -OH and N-acetyl groups; it has been widely studied for the removal of various pollutants [49]. The present study aims to characterize the Fe/ZnO-shrimp shell nanocomposite using X-ray diffraction (XRD), Fourier transform infrared spectrometry (FTIR), and scanning electron microscopy (SEM) through energy-dispersive X-ray analysis (EDX) to investigate dye removal at different adsorbent dosages, initial pH, dye initial concentration, and contact time. ...
... The chemical or physical adsorption mechanism is often an essential indicator in describing adsorption kinetics and adsorbent-pollutant interactions (Guibal et al. 2003;. Furthermore, comprehension of the sorption mechanism plays a vital role in determining rate-limiting steps, optimal sorption conditions, and design purposes Subhan et al. 2021). ...
... And some type of isothiazolinones was also detected by gas chromatography and Raman spectroscopy on glass surface (Sohn et al. 2023). These phenomena would significantly increase the threat to human health (Murphy et al. 2012). Several traditional strategies, including physical or chemical adsorption and biological treatment, have been employed to eliminate antibiotic contamination for many years. ...